Warning signal generator



Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE 2,063,872 WARNING SIGNAL GENERATOR tion of New York Application February 4, 19:35, Serial No. 4,908 3 Claims. (Cl. 116-138) This invention relates to a warning signal of a type primarily intended for use in connection with automotive vehicles; the present invention aiming to provide a functionally and struc- 5 turally improved apparatus to be connected to the intake manifold of an internal combustion motor,A or to any other suitable source of suction.

It is well appreciated by those conversant with the art that considerable difficulty has been experienced in producing a suction operated Warning signal or horn which would operate in a satisfactory manner. More particularly it has been customary to furnish a horn, thel mechanism of which was connected to the intake manifold of a motor so that the suction within such manifold would cause air to be drawn through the mechanism. In most instances it was found that even under ideal conditions the volume of air 2O flowing through the mechanism would be insufficient to cause a proper actuation thereof. Of course, when the suction Within the intake manifold dropped below a certain point (as, for example, when the throttle valve would be opened to too lgreat an extent), no operation of the mechanism could result. Attempts to overcome this difculty by enlarging the connection to the intake manifold have been entirely unsatisfactory for the following reasons: First, that the inrush of air to the motor Would result in too great a dilution of the combustible mixture; second, when the degree of vacuum within the manifold fell below a certain point no satisfactory operation of the mechanism could.- in

- any instance occur.

With this in mind, a solution of the diiliculty has been attempted by interposing between the mechanism and the intake manifold a tank or reservoir, the connection between one end of the tank and the manifold being either constant or else merely provided with a check valve which would prevent the flow of fluid from the manifold to the tank. The connection between the mechanism and the other end of the tank has usually included a valve. Thus, even if only a small passage is provided between the tank and the intake manifold, a suction will be created and built up within the tank or reservoir. This occurs because the valve between the tank and mechanism would normally be closed. In case the throttle valve of the motor were opened to too .great an extent and the suction within the manifold dropped, no appreciable diminution in the degree of vacuum existing within the reservoir 55.' would occur, this being especially true if a check valve is employed. Thus the operator, by simply opening the valve between the reservoir and the mechanism, could secure operation of the latter even if at that moment the throttle valve were opened to a large extent (with relatively low motor speed) and such operation would not result in detrimental dilution of the explosive mixture.

The provision of such a reservoir or tanks has, however, not been an ideal solution of the problem because in the rst instance such apparatus occupies a relatively large amount of space under the hood of an automobile, thus rendering the motor and associated parts relatively inaccessible. Second, considerable cost is involved in providing this apparatus and, third, it'has frequently occurred that the yapparatus when once installed, has rattled or otherwise audibly vibrated, and additionally, the apparatus has frequently developed air leaks. 20

With the foregoing in mind, the present invention aims to provide a warning signal of the vacuum type which may be employed in connection with the automotive vehicles such, for example, as automobiles, and which mechanism will op- 25 erate effectively without utilizing any tanks or reservoirs and irrespective of whether the throttle valve of the motor has been over-opened in the particular moment that it is desired tol actuate the warning signal. 30

A further object of the invention is that of furnishing a mechanism of this typewhch will embody relatively few parts, each individually simple and rugged in construction and capable of assemblage at little expense. Moreover, the apparatus thus furnished may be installed by re1- atively unskilled labor and will operate over long periods of time Without need of replacement, adjustment, or repairs.

With these and other objects in mind, refer- 40 ence is had to the attached sheet of drawings illustrating one practical embodiment of the invention and in which:

Fig. 1 is a sectional side View of the apparatus;

Fig. 2 is a transverse sectional view taken 45 along the lines 2-2 in the direction of the arrows in Fig. 1; f

Fig. 3 is a face view of the diaphragm which may be employed;

Fig. 4 shows the valve mechanism which co operates with such diaphragm;

Fig. 5 is a fragmentary sectional View showing certain of the parts as illustrated in Fig. 1 under operating conditions, and

device or operating member.

In these views the numeral indicates generally the apparatus which includes in the illustrated embodiment casing sections 2| and 22. These sections receive the sounding apparatus hereinafter described and they are subsequently locked against the possibility of accidental operation by, for example, having section 2| formed with a flange 23 and extending the adjacent edge portion of section 22 around this flange as at 21 and pressing the parts together. Such procedure will serve to also anchor the mechanism hereinafter referred to, and at this time it will also be noted that the section 2| may have a shoulder portion 26 and adjacent its end a flange 24 serving to retain a nut 25 which, together with a suitable backing fiange and clamping nut serves to secure the end of a conduit 32'; the latter being thus connected to the casing.

Section 22 is formed with a centrally disposed opening 29 and a projector or trumpet 28 is mounted upon this section in line with this opening as, for example, by utilizing a collar member 30 and bolts 3|. Accordingly, it will be understood that air may enter through the projector 28 and opening 29, passing thence through the casing and so through the outlet 32 of the boss or nut and thence to the tube 32. In order to secure such a flow of air, the tube may be connected to any suitable source of suction as, for example, a motor which has been generally indicated at 48 and which has an intake manifold 48 and a. tap 50 for the coupling of the tube.

Disposed between the casing sections is a diaphragm 33. This may be formed of flexible or substantially rigid material and is provided with a central opening 38. A valve member or head generally indicated at 40 includes a body 34 and a flange portion 42, the diameter of such flange being less than the diameter of the opening 38, and the area of the head 34 being in excess of the area of the diaphragm opening. This ange--which in certain respects might be likened to a plunger, is mounted as, for example, by securing to the same a spider 35 formed of resilient material and which spider has its arms resting upon theshelf or shoulder 26 as has been indicated at 4|.

Arranged to each side of the diaphragm are shims 36 formed of any desirable material and which serve not alone to prevent air leakage, but also mount the diaphragm against any possibility of rattling. Interposed between the rear face of the diaphragm and the adjacent shim is a spacing member 31. This member has a central opening preferably of the same general area and shape as the opening 38 of the adjacent diaphragm. Interrupting the edges of the opening 43 are recesses 44, which extend materially beyond points to which the body of the plunger or valve 34 extends and consequently this body will be incapable of sealing the spaces 44 and as a result the member 31 provides an air passageway device through which air may always flow.

The diaphragm and its associated parts divide the casing into chambers 39 and 39. In the operative condition of the mechanism as shown in Fig. 1, the valve head or plunger, generally indicated at 40 in Fig. 4 has its flange portion or base bearing against the air passageway device shown in Fig. 6. The opening 43 of this device may have the same diameter as the opening 38 of the diaphragm or it may vary with respect thereto.

a'oeasve In any event, however, the flange or projecting portion 42 of the valve head has a diameter less than that of the openings 38 and 43 although the base portion of this memberand especially the outwardly extending edges thereofembrace an area in excess of these openings. Such area, however, is less than the distance between the bases of the opposed notches or indentations 44 formed in the member 31.

Consequently, although the main openings through the diaphragm and spacing member are closed by the valve or plunger when the latter is in normal position, small openings are left incident to the fact that the plunger does not cover the notches 44 and the latter, of course, communicate with the opening 38. Consequently, if the valve (not shown) within tube 32' is opened and even if only a small amount of suction exists within the intake manifold or its equivalent, air will immediately begin to flow through the space existing between the outer face of flange 42, the edge of diaphragm opening 38, and the edges defined by the notches or indentations 44.

It is customary in providing warning signals of this type, to utilize at least a pair of mechanisms, the frequencies of which may be attuned to provide a harmonious or attention-arresting sound which shall not be objectionable but will have relatively great carrying power. The following dimensions are suggested with the common twin intallation in mind. If a single horn or three or more horns are employed, the general proportions herein indicated should be followed; it being in all instances desirable to have the eective area of the valve mechanism when open less than the effective area of the outlet opening or tube, and/ or nipples connecting the same to the source of suction. Thus, considering the nipple to have a bore equivalent to .06201 square inch, the valve area of each of a pair of warning mechanisms should be equal to .03015 square inch, so that the combined valve area when open of said mechanisms is equal to .0603 square inch which is less than the effective area of the outlet opening. 'Ihe air passageway device prevents the plunger or head 40 from approaching the diaphragm any closer than .002 inch.

Thus, with only a minor degree of suction resulting in an air flow of relatively slow velocity through the tube 32', such ow will cause the plunger 40 to be unseated from the member 31, it being appreciated in this connection that a Venturi-like effect is produced through the valve mechanism which causes the normal and relatively slow velocity air flow to be materially enhanced at this point. If the diaphragm and the adjacent unit 31 are relatively flexible these parts will initially move rearwardly with the plunger 46. Thereafter and against the continuing resistance of the spider 35 which bears against the shoulder 26 as indicated at 4|, the plunger will continue its rearward movement, while the diaphragm and spacing member (having reached their limits of elastic movement) will not continue their rearward movement. The plunger will not vibrate in the air stream, it being understood that it has moved rearwardly to a point representing the maximum effective opening of the valve mechanism. Of course, if a relatively rigid and spacing member is employed, no movement of these parts will occur.

In any event, sound will be produced by this mechanism incident to any one or a combination of the following factors: first, vibration of the diaphragm and the spacing member; second, contact between these elements; third, contact between the spacing member and the plunger; fourth, reciprocaton of the plunger, and lifth, the consequent decrease and increase in air volurne and velocity as the plunger so reciprocates. These movements, of course, occur at audibly perceptible frequencies and result in a pulsation of the air column dened by the trumpet 28, opening 23, and chamber 39. Such pulsation, of course, causes the desired warning note to be produced.

t is obvious that numerous changes in construction and rearrangements of the parts might be resorted to without departing from the spirit of the invention as defined by the claims.

What is claimed is:-

1. A warning signal including a casing having inlet and outlet ports, the latter to be connected to a source or" suction, a vibratory diaphragm within said casing and provided with aA centrally disposed opening permitting a oW of air from said inlet port to said outlet port, a reciprocable plunger valve Within the casing and having a portion oi its body extending through said diaphragm opening to vary the movement of air therethrough, the remainder of said valve lying adjacent the diaphragm face and means for constantly maintaining said plunger spaced with respect to saiddi-aphragm whereby air may, under all circumstances, flow through said diaphragm opening.

2. A warning signal including a casing having inlet and outlet ports, the latter to be connected to a source of suction, a vibratory diaphragm Within said casing and provided With a centrally disposed opening permitting a new of air from said inlet port to said outlet port, a reciprocable plunger valve within the casing and having a portion of its bodir extending through said diaphragm opening to vary the movement of air therethrough, the remainder of said valve lying adjacent the diaphragm and means for constantly maintaining said plunger spaced with respect to said diaphragm, whereby air may under all circumstances How through said diaphragm opening the effective area of the diaphragm opening when uncovered to the greatest extent being less than the effective area of said outlet opening.

3. A Warning signal generator including a casing having inlet and outlet openings, an apertured vibratory diaphragm disposed within the casing and through which aperture air flows in its passage from the inlet port toward said out- Alet port, a reciproc'able plunger mounted within said casing and adjacent said diaphragm for varying the air flow through said aperture, a sleeve forming a part of said plunger and eX- tending thro-ugh said aperture and spaced from the edges thereof to maintain the effective area of said aperture opening constant during movements of the plunger, means preventing said plunger from sealing said aperture to assure the constant vmaintenance of an open passageway through such aperture and under all conditions, the effective area of the spaces between the aperture edges and the plunger and plunger sleev(J being less than the effective area of the outletI opening.

ALEXIS F. GILLET. 

